1. Field of the Invention
This invention relates to a cover for the opening in the roof surface of a motor vehicle and a corresponding method for manufacturing such a cover.
2. Description of Related Art
Glass covers for motor vehicle roofs in which the glass pane is foamed in its peripheral edge area have been known for a long time. Examples of these generic covers are described in published German Patent Application DE 37 42 719 A1, German Patent DE 43 08 215 C1 which corresponds to U.S. Pat. No. 5,524,955, published German Patent Application DE 35 06 009 A1 which corresponds to U.S. Pat. No. 4,738,482, German Patent DE 100 36 630 C1 which corresponds to U.S. Pat. No. 6,540,289, German Patent DE 199 18 150 C1, and published German Patent Application DE 197 44 385 A1. In all these references, glass covers are disclosed in which an inside cover sheet which is used for reinforcement and attachment of the glass pane is foamed in at the same time.
In published German Patent Application DE 37 42 719 A1 and the U.S. Pat. No. 6,540,289, the inside cover sheet has a bulge or a bead by which the inside cover sheet rests on the bottom of the glass pane. In this way, the penetration of the foam mass in the direction to the middle area of the glass pane can be limited. In this manner, the inside cover sheet toward the middle area of the glass pane projects beyond the peripheral foam. This arrangement is also described in the German Patent DE 199 18 150 C1.
In the cover described in U.S. Pat. No. 5,524,955, a foam strip is inserted between the inside cover sheet and the bottom of the glass pane in order to limit the penetration of the foam mass in the direction to the middle area of the glass pane. The same effect is achieved in the cover described in the U.S. Pat. No. 4,738,482 by a sealing profile which is inserted between the inside cover sheet and the bottom of the glass pane.
Published German Application DE 197 44 385 A1 discloses a cover in which the peripheral foam has a very small undercut which is not detailed, and which points toward the middle area of the glass pane.
When the glass pane of a glass cover breaks, a collar of slivers generally forms on the edge of the peripheral foam or the inside cover sheet, the edges of the slivers pointing toward the middle area of the cover. In other words, when the glass pane breaks, an accumulation of glass slivers project toward the inside and toward the middle area of the cover from the edge of the peripheral foam or of the inside cover sheet, the edges pointing toward the middle area of the cover. Such formation of slivers is hazardous to the passengers, and in the case of an accident, also for the rescuers assisting the passengers.